It can be alarming to notice a soft blue or purple lump on your child’s gums just before a tooth comes through. The good news is that this is often an eruption cyst—a common and usually harmless condition that often resolves on its own.
What is an Eruption Cyst?
An eruption cyst is a small, fluid-filled swelling that forms over a tooth as it is about to erupt through the gum. It most commonly affects children when their baby teeth or adult teeth are coming in, but it can occasionally occur in adults.
If a small amount of blood mixes with the fluid, the cyst may appear blue or purple. This is sometimes called an eruption haematoma.
What Does It Look Like?
An eruption cyst usually appears as:
- A soft, smooth swelling on the gum.
- Blue, purple, pink, or clear in colour.
- Located directly over an erupting tooth.
- Usually painless, although it may feel tender if bumped while eating or brushing.
In most cases, the tooth can be seen or felt just beneath the swelling.
Does It Need Treatment?
Most eruption cysts do not require treatment. As the tooth continues to erupt, it usually breaks through the cyst naturally, allowing the swelling to disappear.
It’s important not to try to burst or drain the cyst at home, as this can introduce bacteria and increase the risk of infection.
When Should You See a Dentist?
Although eruption cysts are usually harmless, you should arrange a dental examination if:
- The swelling becomes very painful.
- There is increasing redness, pus, or signs of infection.
- Your child develops a fever.
- The tooth does not erupt as expected.
- The swelling continues to enlarge or doesn’t resolve.
In rare cases, if the cyst is preventing the tooth from erupting or is causing significant discomfort, your dentist may gently open the cyst to help the tooth come through.
Can Eruption Cysts Be Prevented?
Eruption cysts are a normal part of tooth development and cannot usually be prevented. The best approach is regular dental check-ups so your child’s developing teeth can be monitored.
The Bottom Line
Finding a blue lump on your child’s gums can be worrying, but eruption cysts are usually a normal part of the tooth eruption process and often disappear without treatment.
At Dural Dental Practice, we’re here to make every stage of your child’s dental development as smooth as possible. If you’re unsure whether a swelling is an eruption cyst or something else, our friendly team can assess it and give you peace of mind.
